1. Field of the Invention
The present invention relates to a magnetic recording and reproduction apparatus such as a video cassette recorder having excellent high density recording and reproduction characteristics and to a magnetic head mounted to the apparatus.
2. Description of Background Information and the Prior Art
Recently, a magnetic recording and reproduction apparatus such as a video cassette recorder or a hard disk drive tends to record and reproduce signals at a higher density to and from a magnetic recording medium so as to provide a compact apparatus having a large storage capacity. Then, in a field of magnetic recording medium and magnetic head, many workers perform research and development to improve recording and reproduction characteristics in a high record density region.
In order to improve a resolution for recording and reproduction in a high recording density region to and from a magnetic recording medium, it is required to increase remnant magnetization of a magnetic layer of the medium accompanied by the increase in coercive force and the decrease in thickness of the magnetic layer in correspondence to the increase in remnant magnetization. Especially, thin film magnetic recording media prepared with vacuum evaporation, sputtering, ion plating or the like have attracted attention owing to their performance exceeding a limit of prior art coat-type magnetic recording medium.
As to the magnetic head, a soft magnetic material having a higher saturation magnetic flux density is developed in order to improve recording performance in correspondence to a higher coercive force of magnetic recording medium. A ring-type magnetic head having a soft magnetic material with saturation magnetic flux density exceeding 1.5 T is already used practically.
An evaporation tape used for a Hi-8 video cassette recorder is a representative of thin film magnetic recording media. A characteristic of the magnetic recording media is that axis of easy magnetization is oblique relative to a film normal of a magnetic layer thereof in contrast to prior art longitudinal recording media. That is, the axis of easy magnetization is not in a film plane or along a film normal of the magnetic layer, but along a direction oblique relative to the film normal. For example, in a deposition tape for a Hi-8 video cassette recorder, the axis of easy magnetization is oblique by about 70.degree. relative to the film normal in a normal plane including a longitudinal direction of the tape.
Magnetization recorded by a ring-type magnetic head remains along the axis of easy magnetization, and provides a magnetization mode different from that of prior art longitudinal recording. Such oblique magnetization mode improves characteristics at high recording densities relative to prior art longitudinal recording media. As the superiority of the oblique magnetization mode relative to the longitudinal magnetization mode becomes clear, it is also attempted to improve characteristics at high recording densities by realizing oblique magnetization mode for prior art coat-type media.
A magnetic recording and reproduction apparatus tends to be developed to record signals at a higher density for providing a more compact apparatus having a larger storage capacity. Then, in a magnetic recording and reproduction system with a combination of a magnetic head and a magnetic recording medium, it is required more and more to provide a higher S/N ratio, especially in a region of higher linear recording densities.